I. Field of the Disclosure
The present disclosure relates generally to the liquefaction, and specifically selective liquefaction, of the biomass and biomass-derived products, such as lignin. More specifically, but not exclusively, the present disclosure relates to and provides inventive work covering the selective liquefaction of biomass and biomass products, for example lignin, in presence of a homogeneous and environmentally friendly carbon dioxide catalyst in supercritical state and heterogeneous inorganic catalyst or a mixture of heterogeneous inorganic catalysts in water at sub-critical, near-critical, or supercritical condition providing an ability to tune the selectivity and the yield of the organic phenolic compound or a specific and limited range of the organic phenolic compounds.
II. Description of the Prior Art
Lignin is one of the most abundant natural biopolymers produced from biomass and a major non-fossil and carbon-rich renewable source of aromatic compounds. Different processes for lignin or biomass degradation, gasification, or liquefaction and their conversion into high-value organic products are known. Degradation, gasification, or liquefaction of lignin and biomass using sub-critical, near-critical, and supercritical conditions are known.
WO2011/091044 discloses production of fermentable sugars and lignin from biomass using supercritical fluids. An optional addition of less than 10% of carbon dioxide (as an additive) in the pretreatment step in the range of 150-300° C. is considered. However, the selectivity approach in regard to production of one specific phenolic product or a number of specific phenolic products is not disclosed. Furthermore this patent is not related to the production of high-value phenolic products.
EP 2449060 A2 discloses a supercritical water gasification process and in particular catalytic gasification of organic matter in supercritical water in presence of metal catalysts supported on metal oxides (Al2O3, MnxOy, MgO, ZrO2, and La2O3) and broad range of alkali salts producing gaseous products in the processes of steam reforming, methanation, and hydrogenation.
An example is provided for p-cresol (4-methylphenol) producing gaseous products such as H2, CO, CH4 and CO2. However, this patent is not related to the liquefaction of the said organic matter and the selectivity approach in regard to production of one specific phenolic product or a number of specific phenolic products is not disclosed.
U.S. Pat. No. 8,945,246 discloses an apparatus for producing liquefied fuel oil from lignocellulose biomass using specific organic solvents including paraffins, cyclic hydrocarbons, aromatic hydrocarbons, alcohols, phenols, ethers, ketones, esters and combination thereof. However, the '246 patent does not disclose a selectivity approach in regard to production of one specific phenolic product or a number of specific phenolic products.
None of the prior art techniques disclose selective synthesis of one specific phenolic product or a number of specific phenolic products that can be achieved by synergistic combination. As such, limitations in these and other non-enumerated areas have and do continue to exist with the current methods and approaches.